Thousands of shoes fell off the ship that was carrying ...

[Pages:3]The Ocean in Motion ? 2018 The Regents of the University of California. All rights reserved. Image Credit: Arie Ouwerkerk/AFP/Getty Image.

Thousands of shoes fell off the ship that was carrying them across the ocean. Eventually, some of those shoes washed up on this beach. People collected them and tried to find matched pairs.

The Ocean in Motion

Surprising things sometimes wash up on shore, and this can happen all over the world. During a powerful storm in 1990, containers packed with 61,000 shoes fell off a cargo ship travelling across the Pacific Ocean and eventually washed up on beaches in Oregon, Hawaii, and Japan. These locations are hundreds or thousands of miles away from the place where the shoes were spilled. How did the shoes make their way to these locations?

If you look at a photograph of Earth, most of what you see is the big, blue ocean--after all, the ocean covers 71% of our planet. In a photograph or on a map, it may not look like the ocean moves very much, but the opposite is actually true. The water in the ocean is always

The ocean covers 71% of Earth and is in constant motion. The movement of the ocean carries energy and objects wherever it goes.

1 The Ocean in Motion

The Ocean in Motion ? 2018 The Regents of the University of California. All rights reserved. Image Credit: NASA Goddard Space Flight Center.

moving from place to place, carrying objects and organisms wherever it goes. Ocean water doesn't move randomly; it flows in consistent patterns. Scientists call ocean water flowing in a continuous path an ocean current. Currents carry all kinds of objects and organisms all over the world. The shoes made their way across the ocean with the help of ocean currents.

In addition to objects and organisms, ocean currents carry energy from the sun all around Earth. In fact, the motion of water around Earth's ocean is one of the main ways energy moves around the planet. Energy from the sun is transferred to the ocean surface. As the currents move across Earth's surface, the energy moves with them.

The current shown on the map at the top of this page is moving away from the equator. At the equator, a large amount of energy is transferred from the sun to the ocean's surface. As the current moves north, it carries this energy with it. If you place your finger on the map anywhere where this current moves, the water there would be warmer than you would expect for a location at this latitude because of the current that moves through this area.

The current shown on the map at the bottom of this page is moving away from the South Pole. The farther away from the equator you are, the less energy is transferred from the sun to the ocean surface, with the least amount of energy transferred at the poles. This means the current traveling from the South Pole carries less energy with it than currents coming from the equator. If the ocean water weren't moving, then ocean surface temperatures in different locations would only depend on their latitudes. However, in locations where a cold current moves past, the ocean surface temperature is lower than you would expect.

Japan

North Paci c

Equator

Australia

South Paci c

KEY warm current

A warm current moving north from the equator keeps Japan warmer than other places at the same latitude.

Indian Ocean

Equator

Australia

KEY cool current

Antarctica

A cold current traveling north from Antarctica keeps the western coast of Australia cooler than other locations at the same latitude.

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The Ocean in Motion ? 2018 The Regents of the University of California. All rights reserved. .

Ocean currents form five main gyres, or circles: the Indian Ocean Gyre, the North Pacific Gyre, the South Pacific Gyre, the North Atlantic Gyre, and the South Atlantic Gyre.

The maps on this page make it look like ocean currents are constant. However, ocean currents can sometimes change direction. Since ocean currents carry energy around Earth, a change in the direction a current moves can change ocean surface temperatures at any locations the current passes on its journey.

In many parts of the ocean, surface currents come together to form gyres, huge areas of water moving in big circles. All together, these gyres move water in a predictable pattern all over the globe, carrying energy, organisms, and other objects with them. That's how shoes that were spilled in the middle of the ocean can end up in Oregon, Hawaii, and Japan!

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